End brush assembly



Jan. 14, 1969 A. J. MARTIN 3,421,172

END BRUSH ASSEMBLY Filed Feb. 9, 1968 v v INVENTOR E ANGELO JOSEPH MARTIN United States Patent Claims ABSTRACT OF THE DISCLOSURE A power driven rotary hollow end brush comprising an annular brush element and a holder therefor, adapted to be mounted upon a twist drill or like tool.

This invention relates as indicated to a power driven rotary end brush and more particularly to such an end brush which is adapted to be mounted upon a twist drill or similar tool to act upon the surface of the work in the region immediately adjacent such tool.

A tool of a somewhat similar type is disclosed in Nelson Patent 3,142,080 and the present invention relates to further improvements in brushes of this general type. When bolt holes, for example, are drilled in automotive frame and body members, for example, it is often important that the immediately surrounding surface area be cleaned of foreign coatings such as may be left thereon in the form of rubber flash, in order that the head of the bolt subsequently inserted therethrough may tightly engage the metal part. For this purpose, an appropriate brushing tool may desirably be mounted directly upon the drill to perform the surface cleaning operation immediately upon completion of the drilled opening. It has been found that relatively large gauge (e.g. .O.025" diameter) straight carbon steel wire bristles are especially effective for such purpose. It is accordingly an object of this invention to provide a power driven rotary hollow end brush of the type described which will be inexpensive of manufacture.

A further object is to provide such end brush which may be very quickly and readily mounted upon a twist drill or like rotary tool for the aforesaid brushing operation. Still another object is to provide a rotary end brush assembly including a holder member releasably securing such brush in place upon the tool. Other objects of theinvention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

FIG. 1 is a side elevational view of the new brushing tool of this invention showing the same mounted upon a twist drill.

FIG. 2 is an enlarged longitudinal section of such brushing tool taken on the line 2-2 of FIG. 1.

FIG. 3 is a similar longitudinal section of the brush element taken on the line 33 of FIG. 2, and

FIG. 4 is an end view of the FIG. 3 brush element.

Referring now more particularly to said drawing the embodiment of the invention there illustrated comprises a brush element having an inner tubular portion 1 and a shorter outer tubular portion 2 of greater diameter than such inner tubular portion and concentrically encircling the latter with an end portion 3 of the inner tubular portion protruding axially therefrom. Brush material in the form of straight hard carbon steel wire bristles 4 which may desirably have a Knoop hardness of approximately 680 fills the annular space between such concentric tubular portions 1 and 2 and extends therebeyond in a direction opposite to the direction in which the inner tubular portion 3 protrudes. The basal portions of the wire bristles 4 are bonded together and also bonded to tubular portions 1 and 2 as by brazing 5; other appropriate bonding materials may also be employed such as epoxy resin cements, for example. The protruding portion 3 of the inner tubular portion is provided with lateral apertures 6 and 7 which have a purpose to be explained.

A holder for such brush element comprising a relatively thick-walled tubular member 8, ordinarily of steel, as are tubular portions 1 and 2, is provided with a slightly enlarged bore 9 extending inwardly from one end thereof adapted closely to fit over the protruding end portion 3 of the brush element with the remainder 10 of the bore of the holder member being of the same diameter as the inner diameter of portion 3. Such holder member 8 has a pair of diametrically opposite laterally threaded apertures 11 and 12 therein adapted to be aligned with the aforesaid apertures 6 and 7 in portion 3 when the holder member is fitted over the latter and abuts against the adjacent end of the outer tubular portion 2. The bore of the holder member 8 at the end thereof adjacent the brazed basal portion 5 of the body of brush material is further enlarged at 13 to accommodate the bonding means there exposed.

When mounted upon a twist drill 14, for example, as shown in FIG. 1, set screws 15 and 16 are threadedly engaged in corresponding apertures 11 and 12 of the holder member 8, passing through apertures 6 and 7 in the protruding brush element portion 3, and firmly engaging the flutes of the drill to secure the end brush assembly in selected position thereon against relative rotation and axial displacement.

The component parts of this new brush assembly are, of course, very inexpensive and involve no special forming operations or difiiculties in assembly. The inner diameter of the composite brushing tool is uniform throughout, enabling quick mounting on a twist drill or like tool and closely fitting the latter. The annular brush end face accordingly acts upon the work surface directly adjacent such drill. The holder 8 and inner portion 1 together present a long continuous metal inner surface engaging the drill for increased strength, rigidity and stability in use.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I therefore, particularly point out and distinctly claim as my invention:

1. A rotary hollow end brush adapted to be mounted upon a twist drill or like tool comprising a brush element and a separable holder therefor, said brush element comprising an inner tubular portion, a shorter outer tubular portion of greater diameter than said inner tubular portion concentrically encircling the latter with an end portion of said inner tubular portion protruding axially therefrom, and brush material secured in and filling the annular space between said concentric tubular portions and extending therebeyond in a direction opposite to the direction in which said inner tubular portion protrudes, said protruding portion of said inner tubular portion having a lateral aperture therein, and said holder comprising a relatively thick-walled tubular member adapted to fit over said protruding end portion of said inner tubular portion and abut against the adjacent end of said shorter outer tubular portion, said holder member having a lateral threaded aperture therein adapted to be aligned 3 with the aforesaid aperture in said protruding end portion when said holder member is thus fitted over said protruding end portion, and screw means threadedly engaged in such aperture in said holder member and extending inwardly through such aligned aperture in said protruding end .portion to engage such drill.

2. A rotary hollow end brush comprising a brush element and a holder therefor, said brush element comprising an inner tubular portion, a shorter outer tubular portion of greater diameter than said inner tubular portion concentrically encircling the latter with an end portion of said inner tubular portion protruding axially therefrom, brush material filling the annular space between said concentric tubular portions and extending therebeyond in a direction opposite to the direction in which said inner tubular portion protrudes, and means bonding the basal portion of the brush material together and also bonding said tubular portions together to form a unitary brush element, said protruding portion of said inner tubular portion having a lateral aperture therein, and said holder comprising a relatively thick-walled tubular member having a slightly enlarged bore extending inwardly from one end thereof adapted closely to fit 'over said protruding end portion of said inner tubular portion with the remainder of the bore of said holder member being of the same diameter as the inner diameter of said inner tubular portion, said holder member having a lateral threaded aperture therein adapted to be aligned with the aforesaid aperture in said protruding inner tubular portion when said holder member is fitted over said protruding tubular inner portion and abuts against the adjacent end of said outer tubular portion, and a screw threadedly engaged in such aperture in said holder member and extending inwardly through such aligned aperture in said inner tubular portion.

3. The brush of claim 2, wherein said brush material comprises straight wire bristles, and the bore of said holder member at the end adjacent the basal portion of said brush material is further enlarged to accommodate said bonding means.

4. The brush of claim 3, wherein the outer diameter of said holder member is the same as that of said outer tubular portion.

5. A rotary end brush comprising an inner tubular portion, a shorter outer tubular portion of greater diameter than said inner tubular portion concentrically encircling the latter and joined thereto with an end portion of said inner tubular portion protruding axially therefrom, brush material filling the annular space between said concentric tubular portions and extending therebeyond in a direction opposite to that in which said inner tubular portion protrudes, means securing said brush material against withdrawal, outer annular reinforcing means fitted around said protruding inner tubular portion, and means for securing said brush on a coaxial member inserted within said protruding inner tubular portion.

References Cited UNITED STATES PATENTS 681,148 8/1901 Stow 15-204 2,927,336 3/1960 Saver 15-180 XR 3,142,080 7/1964 Nelson 15-180 XR FOREIGN PATENTS 531,615 8/1931 Germany.

PETER FELDMAN, Primary Examiner.

U.S. Cl. X.R. 15105, 

